Boruto- Sarada Uchiha vs. Buntan Kurosuki
First off, no, I do not watch Boruto, but I do occasionally catch a few scenes that have been uploaded to YouTube from time to time. Also, spoiler alert for anyone who hasn’t seen episodes 25-32 of Boruto. During the School Trip arc of Boruto, Sarada Uchiha ends up in a fight with a Mist ninja by the name of Buntan. I know that the fighting in Boruto is powered by sparkly magical ninja bullshit, but in this case, it was chemistry that won the day.
During the fight Buntan uses her ninja powers to create electric fish that try to attack Sarada Uchiha as they swim around the lake in the underground cavern they are fighting in.
These fish create bubbles in the water as they swim around, which Sarada Uchiha makes note of.
Setting aside the magic of how electricity can maintain a solid form and also not electrocute Sarada Uchiha, who is swimming in water, what happens when electricity is passed through water?
You guessed it, Electrolysis
Electrolysis is a chemical process that occurs when you pass electricity through an ionic compound that produces a chemical reaction at the positive, and negative electrodes. Yes, I do realize that our magical ninja lightning fish do not have electrodes, but if they did, one end would be the cathode (negative charge) and the other would be the anode (positive charge).
What I am most interested in here is what the electricity is doing to the water. All water, except distilled water, or deionized water, is an ionic solution due to the small amounts of minerals it contains, and it will conduct an electric current. You can test this by hooking up a small lightbulb to a battery and leaving a gap in one of the wires. You then place the gap into a cup of water without the wires touching and the lightbulb will turn on. The more ionic the water is the brighter the lightbulb will be. (I have used a lab based on this for some of my physics classes.)
Given that the battle is taking place in a cavern with an underground lake, it is safe to assume that the lake is full of dissolved minerals from the surrounding rock and will have no problem in conducting electricity. Thus, electrolysis will happen rapidly. The chemical reactions that happen will vary based on the dissolved salts, but here is one example for the electrolysis of water: FYI– Aqueous means dissolved in water
NaCl (aqueous) + 2H2O (liquid) –> 2NaOH (aqueous) + H2 (gas) + Cl2 (gas)
Other times the salt is not directly involved with the reaction but still must be present for it to occur:
2H2O (aqueous) –> 2H2 (gas) + 2O2 (gas)
As you can see in either case hydrogen gas is produced, which are the bubbles that Sarada saw coming off the lightning fish. Since hydrogen gas is lighter than water, the bubbles would rise into the air about the lake, filling the cave with hydrogen gas.
If you read my post on Roy Mustang from FMA, then you know what is going to happen next. Hydrogen is very flammable and will rapidly react with oxygen to make water causing a large energetic explosion:
2H2 (gas) + O2 (gas) –> 2H2O (gas)
Sarada Uchiha even points this out before setting off the explosion, explaining how the lightning fish were causing electrolysis, creating the hydrogen gas, which she then sets on fire.
I would have preferred her to use the term electrolysis instead of ionization, as electrolysis would have been more correct. Sarada Uchiha is right that it takes a certain amount of electricity to occur. Also, a line about its creating hydrogen gas would have been a nice addition. I know it’s probably nit-picking but it is for a good reason and that is that the primary demographic for Boruto probably has never heard of electrolysis. This fight could be used as a teachable moment, as they like to say in education.
This is an interesting case because while the science in theory is correct, there are a number of things missing.
1- Electrolysis is what happens when an electric current is passed through water
2- Electrolysis will create hydrogen gas
3- Hydrogen is explosive and easy to set on fire
1- No cathode or anode
2- Electricity cannot take a shape
1- Ion concentration of the water
2- Size of the lake
3- Electrical power of the lightening shark
4- Amount of time electrolysis is taking place
So, while there are some problems with this one, I want to call it plausible, because it is based on real world science and it gets enough things right that I might actually use it to introduce the topic if I knew my students were anime fans.